For example, in manufacturing of a liquid crystal panel for an image display, various semiconductors, or the like, a sputtering apparatus which forms a thin film of metal on one surface of a substrate is used. The sputtering apparatus is configured in such a manner that the substrate and targets are disposed to face each other inside of a processing chamber maintained at high vacuum, rare gases (Ar gases, etc.) are introduced into the processing chamber as well as a high voltage is applied between the substrate and the targets, and ionized rare gas elements collide with target surfaces, such that atoms of the target surfaces are sprung out to form a thin film of a metallic material of the targets on the surface of the substrate.
In the sputtering apparatus, a part of target atoms sprung out from the targets may be attached to an inner wall of the processing chamber to form an unnecessary metal film on the inner wall. Therefore, conventionally, a deposition preventive plate is disposed inside of the processing chamber to isolate between the inner wall and a processing region, and prevents the metal film from being deposited on the inner wall by allowing for a film deposition on the deposition preventive plate.
Meanwhile, for example, in manufacturing of the liquid crystal panel, when using a large-size glass substrate, and depositing a thick metal film by a material having high conductivity such as Cu, a processing time is long, and a temperature in the processing chamber reaches a high temperature.
Therefore, the deposition preventive plate disposed as described above is formed by arranging a plurality of component plates of which respective end portions are overlapped with each other at a gap, so as to absorb a thermal expansion due to film deposition processing by a relative movement of each component plate in a direction of the overlapped width.
In the deposition preventive plate configured as described above, the gap of the overlapped portion of the component plates functions as a labyrinth gap to seal the processing region side and the inner wall side. In order to enhance the sealing function, it is preferable to set to be a small gap of about several mm. Meanwhile, since the metal film is also attached to the gap, the attachment sites of the metal films contact with each other due to the relative movement at the time of thermal expansion, and further due to a thermal deformation of the component plates, such that the metal films are peeled-off and mixed into a film being formed on the substrate, and thus a problem of a deterioration in a film deposition quality occurs.
When the above-described problem occurs, it is necessary to be forced to take measures such as a replacement of the deposition preventive plate, and to take a pause of an operation of a film deposition apparatus during this period, as well as there is a problem that a decrease in an operation rate may occur.
These problems may be solved by increasing the gap of the overlapped portion of the component plates. However, the sealing function is insufficient, and the target atoms in a film deposition region are sprung out to an outside, such that the deposition preventive plate may not serve the original function to prevent the unnecessary film deposition on the inner wall of the processing chamber.
Further, the above-described problems also occur in a vacuum deposition apparatus such as a chemical vapor deposition (CVD) apparatus, a physical vapor deposition (PVD) apparatus or the like.
In consideration of the above-mentioned circumstances, it is an object to provide an aspect of disclosure of a film deposition apparatus that can prevent peeling off of a metal film occurred in a structure for absorbing a thermal expansion, while maintaining a sufficient sealing function by a deposition preventive plate, and enables film deposition processing at a high operation rate.
According to one embodiment of the present disclosure, there is provided a film deposition apparatus comprising, a deposition preventive plate which is located in a processing chamber performing film deposition processing on a substrate so as to surround a processing region in the processing chamber for processing on the substrate, and which prevents a film deposition material from being attached to an inner wall of the processing chamber, wherein the deposition preventive plate is configured by arranging a plurality of component plates of which respective end portions are overlapped with each other at a gap, such that a thermal expansion generated due to the film deposition processing is absorbed by a relative movement of an overlapped part in two adjacent component plates of the plurality of component plates in a width direction of the overlapped part, and a concave part is provided at the overlapped part to make the gap provided in a side communicating with the processing region be larger than that provided in the other side.
The overlapped part in the component plates forming the deposition preventive plate is provided with the concave part. The concave part makes the gap between the component plates provided in the side communicating with the processing region be larger than that provided in the other side. In the overlapped part in the component plates, metal films are formed on facing surfaces thereof with the processing region during film deposition processing. The sites where metal films are formed are the facing surfaces of the overlapped part having an expanded gap by the concave part, and a possibility of contacting with each other when the component plates move relative to each other for absorbing thermal expansion is low, such that a deterioration in a film deposition quality due to mixing of a peeled-off material could be prevented. In addition, the overlapped part may maintain a sufficient sealing function by the gaps at portions other than the concave part.
In the embodiment of the present disclosure, it is preferred that the concave part is a concave groove which is continued in a longitudinal direction of the overlapped part.
The concave part is formed as the concave groove which is continued in the longitudinal direction of the overlapped part, such that it is possible to prevent the peeling-off of the metal film over an entire length of the overlapped part.
In the embodiment of the present disclosure, it is preferred that thin parts provided in the respective component plate of the two adjacent component plates are overlapped with each other, and a surface facing the processing region in the overlapped part and a surface facing the processing region in non-overlapped part are on the same plane, and a surface facing the inner wall in the overlapped part and a surface facing the inner wall in non-overlapped part are on the same plane.
The overlapped part in the component plates is formed by overlapping the thin parts provided in each component plate with each other. In view of surfaces facing the processing region or the inner wall, the overlapped part and the non-overlapped part become the same level as each other, and thereby a deposition preventive plate which does not have a step could be achieved. The gap of the overlapped part is formed in a crank shape to improve the sealing function by a labyrinth effect.
In the embodiment of the present disclosure, it is preferred that the concave part is provided in one of the thin parts which has the surface facing the inner wall.
When forming the overlapped part by overlapping the thin parts, the object could be achieved by forming the concave part in one of the thin parts which has the surface facing the inner wall.
In the embodiment of the present disclosure, it is preferred that the film deposition apparatus further comprises: a plurality of targets disposed inside of the processing chamber; and a partition plate configured to isolate the respective targets each other, wherein the partition plate is configured by arranging a plurality of component plates of which respective end portions are butted with each other at an interval and connecting two adjacent component plates of the plurality of component plates with the use of a connection cover which is provided so as to bridge butted end portions, such that a thermal expansion generated due to the film deposition processing is absorbed by a relative movement of the two adjacent component plates with respect to the connection covers, and a concave part is provided at either the connection cover and each of the two adjacent component plates to make a gap, between the connection cover and each of the two adjacent component plates, at a region apart from the butted end portions be larger than the gap at a region proximal to the butted end portions, and it is more preferred that, wherein the connection cover connects the two adjacent component plates by loosely fitting axes protruding at a surface of the connection cover into long holes formed in the end portions of the two adjacent component plates by penetrating in a thickness direction, to allow the component plates to move relative to each other within a gap configured for achieving the loosely fitting between the axes and the long holes.
In a sputtering apparatus including a plurality of targets in the processing chamber, the partition plate for isolating the targets each other is provided with thermal expansion absorption parts similar to the mechanism in the deposition preventive plate. In the facing part between each of the component plates and the connection cover, the metal film is formed on the facing surface with the processing region during film deposition processing. The facing surface has a gap set to be large by the concave part, such that the possibility of contacting with each other when the component plates move relative to each other for absorbing the thermal expansion is low, and a deterioration in the film deposition quality due to mixing of the peeled-off material could be prevented.
According to the embodiment of the present disclosure, it is possible to satisfy both of the sealing function by the deposition preventive plate, and a peeling-off prevention of the metal film when the component plates move relative to each other for absorbing the thermal expansion, and achieve the film deposition processing with a high operation rate while maintaining a high film deposition quality.
The above and further objects and features will more fully be apparent from the following detailed description with accompanying drawings.